The membership certificate of the Tsung Sin Kongsi, with an illustration of three Hung coins, forms part of the secret society memorabilia found in the William Stirling Collection. William George Stirling was the Assistant Protector of Chinese in Singapore from 1921 to 1931. The Hung coins were issued by the Hung Society for exclusive use among its members and were not for general circulation. Each member was given three Hung coins as capital.
